HARMFUL? HELPFUL?

Jill U. AdamsSpecial to The Times

Depending ON whom you ask, marijuana is a dangerous drug that should be kept illegal alongside heroin and PCP, or it's a miracle herb with a trove of medical benefits that the government is seeking to deny the public -- or something in between: a plant with medical uses and drawbacks, worth exploring.

As the political debates over medical marijuana drag on, a small cadre of researchers continues to test inhaled marijuana for the treatment of pain, nausea and muscle spasms.

All drugs have risks, they point out -- including ones in most Americans' medicine cabinets, such as aspirin and other pain-relievers or antihistamines such as Benadryl. Doctors try to balance those risks against the potential for medical good -- why not for marijuana as well, they ask.

The truth, these researchers say, is that marijuana has medical benefits -- for chronic-pain syndromes, cancer pain, multiple sclerosis, AIDS wasting syndrome and the nausea that accompanies chemotherapy -- and attempts to understand and harness these are being hampered. Also, they add, science reveals that the risks of marijuana use, which have been thoroughly researched, are real but generally small.

Dr. Donald Abrams, chief of hematology and oncology at San Francisco General Hospital and professor of clinical medicine at UC San Francisco, says he sees cancer patients in pain, not eating or sleeping well, experiencing nausea and vomiting from treatment, and being depressed about their situation. He says he is glad that he lives in California, where use of medical marijuana is allowed by state law, although federal officials continue to raid cannabis dispensaries in the state and scrutinize practices of physicians who specialize in writing cannabis recommendations for patients.

"I can talk to patients about medicinal cannabis [and] I'm often recommending it to them for these indications," Abrams says.

Read on to learn what science has to say about the medical pros and cons, and some mitigating factors, of Cannabis sativa. Pages 6, 7